Preheat the oven to 200°C, gas mark 6. Place the potato wedges in a large non-stick roasting tin, drizzle with 1 tbsp of the oil and cook for 10 mins. Add the sausages and mushrooms, then season. Drizzle with the remaining oil and gently toss together. Return to the oven and cook for a further 15-20 mins. Halfway through the cooking time, turn the sausages and potato wedges and add the tomatoes. Cook until the wedges are crisp and the sausages cooked through. Make 2 gaps in the potato mixture and crack an egg into each. Season and return to the oven for 3-4 mins until the eggs are softly set. Carefully divide the mixture between 2 plates and serve with tomato ketchup.